I have very oily skin. How long will this foundation keep my face looking matte? Also, does anyone know where I could get it for $30 or less?

This foundation is great for oily skin! It claims 24 hour wear I'm pretty sure, but I would say it's more like 6-9 hours. I would recommend a setting powder if you want it to be matte that whole time. You can find it at most drugstores. I bought mine from CVS for under 30. I think it's 15!